Such devices are known to those skilled in the art and are generally used as electrolyser to produce oxygen and hydrogen from water and electricity or as a fuel cell to produce water and electricity from oxygen and hydrogen. Among such devices, ion exchange membrane devices of the AEM (alkaline exchange membrane) and PEM (proton exchange membrane or polymer electrolyte membrane) type can be cited. These devices use a plurality of electrochemical cells in series, stacked between two end plates, along the longitudinal axis of the device, so as to form a stack. Such devices are described, for example, in Patent Publications WO 2011/114094 or US 2013/0122388. In these devices, the structure of an electrochemical cell comprises a frame formed of at least two parts, between which the membrane is held by the clamping of its peripheral area. A pressure is applied along the longitudinal axis of the device to ensure a good contact between the various elements of the cells. The axial pressure is generally applied by pressing, to a greater or lesser degree, the end plates which are connected by axial tie rods mounted around the cells. Consequently, high pressure is applied especially in the peripheral area of the membrane, which may cause it to weaken.
Further, the devices also comprise other support elements, notably supports for the electrodes as described in US 2013/0122388, so that known devices comprise a very large number of elements, which are difficult to manufacture and therefore expensive to produce. Further, the large number of elements makes it difficult to control the sealing between the various reactants and products, while it is evidently desired to avoid mixing hydrogen and oxygen. US 2013/0122388 describes, in particular, the use of a flat sealing gasket arranged at the periphery of the cell, between the frame and a bipolar plate, which makes it difficult to apply uniform pressure and achieve a regular distance between each cell.